Preparation method and application of volatile alcohol compound colorimetric detection card
By integrating MOF materials and chemical indicators into a colorimetric detection card, the problems of slow response speed and high cost in the detection of volatile alcohols have been solved, enabling portable, low-cost, and rapid detection.
Patent Information
- Application Number
- CN202411089313.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-08
- Publication Date
- 2026-02-10
AI Technical Summary
Existing methods for detecting volatile alcohols are slow, costly, and inconvenient to carry, making it difficult to achieve rapid and low-cost on-site detection.
A colorimetric detection card integrating MOFs materials and chemical indicators was developed. The MOFs@indicator composite material was prepared and coated on a support substrate to form a portable colorimetric detection card, which uses color changes to detect volatile alcohols.
It significantly improves the adsorption efficiency and detection sensitivity of volatile alcohols, and is low in cost and fast in response, making it suitable for on-site detection in various scenarios.
Smart Images
Figure CN121499474A_ABST
Abstract
Description
Technical Field
[0001] This application relates to a method for preparing a colorimetric detection card for volatile alcohols and its application, belonging to the field of rapid detection technology for volatile gases. Background Technology
[0002] Volatile alcohols are a class of alcohols that readily evaporate into a gaseous state at room temperature. These compounds belong to the alcohol family in chemical structure and typically contain one or more hydroxyl groups (-OH) bonded to a carbon atom. Common volatile alcohols include methanol, ethanol, isopropanol, and n-butanol. These compounds play important roles in various fields, such as being used as flavorings in the food industry and as drug ingredients in the pharmaceutical field. However, some volatile alcohols are toxic or carcinogenic; high-concentration exposure over a short period may irritate and damage the respiratory and nervous systems, and the emission of some volatile alcohols may pollute the environment, affecting air quality and ecological balance. Therefore, strict management and control of volatile alcohols are necessary during industrial production and use to reduce their potential harm to human health and the environment.
[0003] Unlike typical laboratory detection methods such as gas chromatography and high-performance liquid chromatography, colorimetric sensing methods are widely used for the detection of volatile alcohols due to their fast response, cost-effectiveness, and portability. The basic principle of colorimetric sensors is based on the color change of a specific chemical indicator when it combines with an exposed volatile organic compound. Summary of the Invention
[0004] To enhance the detection capabilities of colorimetric sensors, integrating indicators with nanomaterials can effectively improve the capture of volatile organic compounds and further enhance the detection sensitivity of target analytes. Therefore, this application constructs a portable colorimetric detection card based on a MOF-encapsulated indicator strategy for the stable analysis of volatile alcohols.
[0005] The purpose of this invention is to develop a colorimetric detection card composed of MOF frameworks / chemical indicators for the sensitive detection of volatile alcohol compounds.
[0006] To this end, the present invention first prepares a MOF material, and then prepares a composite material by ultrasonically mixing and stirring cerium ammonium nitrate indicator with the MOFs. The composite material is then added to an aqueous solution and ultrasonically formed into uniform suspension droplets onto a supporting substrate, enabling the development of a colorimetric detection card for volatile alcohol compounds.
[0007] According to one aspect of this application, a method for preparing a colorimetric detection card for volatile alcohols, the method comprising at least the following steps:
[0008] Step I: Mix Zn(NO3)2, 2-methylimidazole, and N,N'-dimethylformamide, place them in a sealed container, and react to obtain MOF materials;
[0009] Step II: Add the MOFs material obtained in Step I to the aqueous solution of cerium ammonium nitrate indicator, stir, and dry to obtain MOFs@indicator material;
[0010] Step III: Mix the MOFs@indicator material obtained in Step II with water to obtain Suspension II, adjust the pH, apply it to the substrate, and dry to obtain a colorimetric detection card for volatile alcohol compounds.
[0011] Optionally, in step I, the mass ratio of Zn(NO3)2 to 2-methylimidazole is 1:1 to 4:1, wherein the concentration of Zn(NO3)2 in N,N'-dimethylformamide is 0.001 to 0.016 mol / L.
[0012] Optionally, in step I, the reaction conditions include:
[0013] The reaction temperature is 120–160°C;
[0014] The reaction time is 20–32 hours.
[0015] Optionally, in step II, the concentration of the indicator is 0.17–0.67 mg / mL;
[0016] The concentration of the MOFs material is 0.67–1.67 mg / mL.
[0017] Optionally, in step II, the stirring time is 6 to 24 hours.
[0018] Optionally, the drying time is 6 to 24 hours; the drying temperature is 40 to 80°C.
[0019] Optionally, the concentration of the suspension is 5–20 mg / mL;
[0020] The pH is 3-4;
[0021] The substrate is selected from at least one of polyvinylidene fluoride membrane, filter paper, and wax printing paper;
[0022] The drying time is 4 to 6 hours;
[0023] The drying temperature is 25–60°C.
[0024] According to another aspect of this application, an application of a colorimetric detection card for volatile alcohols in the detection of volatile alcohols is provided.
[0025] The volatile alcohols are selected from at least one of methanol, ethanol, and isopropanol;
[0026] Optionally, the concentration of the volatile alcohol compound is 1.0 to 50 ppm;
[0027] Optionally, the detection process is as follows:
[0028] After reacting the volatile alcohol colorimetric card with volatile alcohols at room temperature for 10–20 minutes, observe the color change of the volatile alcohol colorimetric card.
[0029] The beneficial effects that this application can produce include:
[0030] 1) The colorimetric detection card of the present invention integrates MOF materials with chemical indicators, and the constructed composite material can significantly improve the adsorption efficiency and detection sensitivity of volatile alcohol compounds.
[0031] 2) The resulting portable colorimetric detection equipment is low in cost, fast in response, and highly stable, and can be widely used in on-site detection in various scenarios.
[0032] In summary, the simple and efficient preparation of this material has significant scientific and practical value. Attached Figure Description
[0033] Figure 1 The colorimetric test card prepared in this application is compared with the color before and after exposure to methanol.
[0034] Figure 2 The XRD patterns of MOFs before and after encapsulation of the indicator in Example 4 of this application are shown. Detailed Implementation
[0035] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0036] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0037] The preparation examples and analytical methods in this application are as follows:
[0038] The MOF materials before and after encapsulation with the indicator were tested using an X-ray diffractometer.
[0039] According to one embodiment of this application, a method for constructing MOF materials is provided:
[0040] A certain amount of Zn(NO3)2 and 2-methylimidazole were weighed sequentially and dissolved in a certain volume of N,N'-dimethylformamide (DMF). The mixed solution was sonicated for 20 min until the solution became clear. Then, the homogeneous solution was transferred to a 100 mL stainless steel reactor lined with polytetrafluoroethylene and heated at 140 °C for 24 hours. After cooling the system to room temperature, the product was washed several times with DMF and ethanol and then heated in a vacuum oven at 60 °C for 12 hours to obtain MOF materials.
[0041] The mass ratio of Zn(NO3)2 to 2-methylimidazole is 1:1 to 4:1, wherein the mass of Zn(NO3)2 is 0.04-0.16 g and the volume of DMF is 10-30 mL.
[0042] According to one embodiment of this application, a method for constructing a MOFs@indicator material is provided:
[0043] Add 5-20 mg of cerium ammonium nitrate indicator to 30 mL of aqueous solution, followed by 20-50 mg of MOF material. Stir the mixture at room temperature for 6-24 hours. Wash the resulting sample several times with distilled water, centrifuge, and then dry it in a vacuum oven at 60 °C for 12 hours to obtain the encapsulated composite material.
[0044] According to one embodiment of this application, the colorimetric detection card is reacted with the target analyte at room temperature for 10 minutes, and the color change of the colorimetric detection card is observed.
[0045] Preparation Example 1: Preparation of Metal-Organic Frameworks (MOFs) Materials
[0046] 0.04 g of Zn(NO3)2·6H2O and 0.04 g of 2-methylimidazole were weighed sequentially and dissolved in 10 mL of N,N'-dimethylformamide (DMF). The mixed solution was sonicated for 20 min until clear. The homogeneous solution was then transferred to a 100 mL stainless steel reactor lined with polytetrafluoroethylene and heated at 140 °C for 24 hours. After cooling the system to room temperature, the product was washed several times with DMF and ethanol and then heated in a vacuum oven at 60 °C for 12 hours to obtain MOF materials.
[0047] Preparation Example 2: Preparation of Metal-Organic Frameworks (MOFs) Materials
[0048] 0.08 g of Zn(NO3)2·6H2O and 0.04 g of 2-methylimidazole were weighed sequentially and dissolved in 15 mL of N,N'-dimethylformamide (DMF). The mixed solution was sonicated for 20 min until clear. The homogeneous solution was then transferred to a 100 mL stainless steel reactor lined with polytetrafluoroethylene and heated at 140 °C for 24 hours. After cooling the system to room temperature, the product was washed several times with DMF and ethanol and then heated in a vacuum oven at 60 °C for 12 hours to obtain MOF materials.
[0049] Preparation Example 3: Preparation of Metal-Organic Frameworks (MOFs) Materials
[0050] 0.12 g of Zn(NO3)2·6H2O and 0.04 g of 2-methylimidazole were weighed sequentially and dissolved in 20 mL of N,N'-dimethylformamide (DMF). The mixed solution was sonicated for 20 min until clear. The homogeneous solution was then transferred to a 100 mL stainless steel reactor lined with polytetrafluoroethylene and heated at 140 °C for 24 hours. After cooling the system to room temperature, the product was washed several times with DMF and ethanol and then heated in a vacuum oven at 60 °C for 12 hours to obtain MOF materials.
[0051] Preparation Example 4: Preparation of Metal-Organic Frameworks (MOFs) Materials
[0052] 0.16 g of Zn(NO3)2·6H2O and 0.04 g of 2-methylimidazole were weighed sequentially and dissolved in 30 mL of N,N'-dimethylformamide (DMF). The mixture was sonicated for 20 min until clear. The homogeneous solution was then transferred to a 100 mL stainless steel reactor lined with polytetrafluoroethylene (PTFE) and heated at 140 °C for 24 hours. After cooling to room temperature, the product was washed multiple times with DMF and ethanol, and then heated in a vacuum oven at 60 °C for 12 hours to obtain MOF materials. Figure 2 This indicates that the prepared MOFs material has good phase purity.
[0053] Example 1: Preparation of MOFs@Indicator Composite Material
[0054] Add 5 mg of cerium ammonium nitrate indicator to 30 mL of aqueous solution, followed by 20 mg of the MOF material prepared in Preparation Example 4. Stir the mixture at room temperature for 6 hours. Wash the resulting sample several times with distilled water, centrifuge, and then dry it in a vacuum oven at 60 °C for 12 hours to obtain the encapsulated composite material.
[0055] Example 2: Preparation of MOFs@Indicator Composite Material
[0056] 10 mg of cerium ammonium nitrate indicator was added to 30 mL of aqueous solution, followed by 20 mg of the MOF material prepared in Preparation Example 4. The mixture was stirred at room temperature for 6 hours. The resulting sample was washed several times with distilled water, centrifuged, and then dried in a vacuum oven at 60 °C for 12 hours to obtain the encapsulated composite material.
[0057] Example 3: Preparation of MOFs@Indicator Composite Material
[0058] 20 mg of cerium ammonium nitrate indicator was added to 30 mL of aqueous solution, followed by 20 mg of the MOF material prepared in Preparation Example 4. The mixture was stirred at room temperature for 6 hours. The resulting sample was washed several times with distilled water, centrifuged, and then dried in a vacuum oven at 60 °C for 12 hours to obtain the encapsulated composite material.
[0059] Example 4: Preparation of MOFs@Indicator Composite Material
[0060] 20 mg of cerium ammonium nitrate indicator was added to 30 mL of aqueous solution, followed by 50 mg of the MOF material prepared in Preparation Example 4. The mixture was stirred at room temperature for 6 hours. The resulting sample was washed several times with distilled water, centrifuged, and then dried in a vacuum oven at 60 °C for 12 hours to obtain the encapsulated composite material.
[0061] Example 5: Preparation of MOFs@Indicator Composite Material
[0062] 20 mg of cerium ammonium nitrate indicator was added to 30 mL of aqueous solution, followed by 50 mg of the MOF material prepared in Preparation Example 4. The mixture was stirred at room temperature for 12 hours. The resulting sample was washed several times with distilled water, centrifuged, and then dried in a vacuum oven at 60 °C for 12 hours to obtain the encapsulated composite material.
[0063] Example 6: Preparation of MOFs@Indicator Composite Material
[0064] 20 mg of cerium ammonium nitrate indicator was added to 30 mL of aqueous solution, followed by 50 mg of the MOF material prepared in Preparation Example 4. The mixture was stirred at room temperature for 24 hours. The resulting sample was washed several times with distilled water, centrifuged, and then dried in a vacuum oven at 60 °C for 12 hours to obtain the encapsulated composite material.
[0065] Example 7: Preparation of Colorimetric Detection Card
[0066] The supporting substrate used was a polyvinylidene fluoride membrane. 5 mg of the composite material was mixed with 1 mL of aqueous solution and sonicated for 30 min to obtain a uniform suspension (concentration of 5 mg / mL). The pH of the solution was adjusted to 3 using hydrochloric acid (0.1 M). 1.0 mL of MOFs@indicator solution was dropped onto the substrate, and after drying, a colorimetric detection card for volatile alcohol compounds was obtained.
[0067] Example 8: Preparation of Colorimetric Detection Card
[0068] The supporting substrate used was a polyvinylidene fluoride membrane. 10 mg of the composite material was mixed with 1 mL of aqueous solution and sonicated for 30 min to obtain a uniform suspension (concentration of 10 mg / mL). The pH of the solution was adjusted to 3 using hydrochloric acid (0.1 M). 1.0 mL of MOFs@indicator solution was dropped onto the substrate and dried to obtain a colorimetric detection card for volatile alcohol compounds.
[0069] Example 9: Preparation of Colorimetric Detection Card
[0070] The supporting substrate used was a polyvinylidene fluoride membrane. 15 mg of the composite material was mixed with 1 mL of aqueous solution and sonicated for 30 min to obtain a uniform suspension (concentration of 15 mg / mL). The pH of the solution was adjusted to 3 using hydrochloric acid (0.1 M). 1.0 mL of MOFs@indicator solution was dropped onto the substrate and dried to obtain a colorimetric detection card for volatile alcohol compounds.
[0071] Example 10: Preparation of Colorimetric Detection Card
[0072] The supporting substrate used was a polyvinylidene fluoride membrane. 20 mg of the composite material was mixed with 1 mL of aqueous solution and sonicated for 30 min to obtain a uniform suspension (concentration of 20 mg / mL). The pH of the solution was adjusted to 3 using hydrochloric acid (0.1 M). 1.0 mL of MOFs@indicator solution was dropped onto the substrate and dried to obtain a colorimetric detection card for volatile alcohol compounds.
[0073] Example 11
[0074] The colorimetric detection card prepared in Example 8 was placed in the designed detection device for detection. With the inflow of methanol gas (methanol concentration 1.0 ppm), after a reaction of 10 minutes, the gas was detected from... Figure 1 As can be seen, the colorimetric test card shows obvious color changes.
[0075] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing a colorimetric detection card for volatile alcohol compounds, characterized in that, The preparation method includes at least the following steps: Step I: Mix Zn(NO3)2, 2-methylimidazole, and N,N'-dimethylformamide, place them in a sealed container, and react to obtain MOF materials; Step II: Add the MOFs material obtained in Step I to the aqueous solution of cerium ammonium nitrate indicator, stir, and dry to obtain MOFs@indicator material. Step III: Mix the MOFs@indicator material obtained in Step II with water to obtain a suspension, adjust the pH, coat it onto the substrate, and dry it to obtain a colorimetric detection card for volatile alcohol compounds.
2. The preparation method according to claim 1, characterized in that, In step I, the mass ratio of Zn(NO3)2 to 2-methylimidazole is 1:1 to 4:1; The concentration of Zn(NO3)2 in N,N'-dimethylformamide is 0.001–0.016 mol / L.
3. The preparation method according to claim 1, characterized in that, In step I, the reaction conditions include: The reaction temperature is 120–160°C; The reaction time is 20–32 hours.
4. The preparation method according to claim 1, characterized in that, In step II, the concentration of the cerium ammonium nitrate indicator is 0.17–0.67 mg / mL; The concentration of the MOFs material is 0.67–1.67 mg / mL.
5. The preparation method according to claim 1, characterized in that, In step II, the stirring time is 6 to 24 hours.
6. The preparation method according to claim 1, characterized in that, The drying time is 6 to 24 hours; the drying temperature is 40 to 80°C.
7. The preparation method according to claim 1, characterized in that, In step III, The concentration of the suspension is 5–20 mg / mL.
8. The preparation method according to claim 1, characterized in that, Step III, The pH is 3-4; The substrate is selected from at least one of polyvinylidene fluoride membrane, filter paper, and wax printing paper; The drying time is 4 to 6 hours; The drying temperature is 25–60°C.
9. The application of the colorimetric detection card for volatile alcohols prepared by the method of any one of claims 1 to 8 in the detection of volatile alcohols.
10. The application according to claim 9, characterized in that, The volatile alcohols are selected from at least one of methanol, ethanol, and isopropanol; Preferably, the concentration of the volatile alcohol compound is 1.0 to 50 ppm; Preferably, the detection process is as follows: After reacting the volatile alcohol colorimetric card with volatile alcohols at room temperature for 10–20 minutes, observe the color change of the volatile alcohol colorimetric card.